The Frequency of Uniparental Disomy in Prader-Willi Syndrome

TLDR

Prader‑Willi syndrome is a genetic disorder presenting with hypotonia, obesity, hypogonadism, and intellectual disability, often diagnosed only after cytogenetic analysis, and while two‑thirds of cases show a paternal 15q11q13 deletion, a minority arise from maternal uniparental disomy. The study aimed to quantify the prevalence of maternal uniparental disomy among patients with Prader‑Willi syndrome using molecular genetics. The authors employed molecular genetic assays to detect uniparental disomy in a cohort of Prader‑Willi patients.

Abstract

Prader—Willi syndrome is a genetic disorder characterized by infantile hypotonia, obesity, hypogonadism, and mental retardation, but it is difficult to diagnose clinically in infants and young children. In about two thirds of patients, a cytogenetically visible deletion can be detected in the paternally derived chromosome 15 (15q11q13). Recently, patients with Prader—Willi syndrome have been described who do not have the cytogenetic deletion but instead have two copies of the 15q11q13 region that are inherited from the mother (with none inherited from the father). This unusual form of inheritance is known as maternal uniparental disomy. Using molecular genetic techniques, we sought to determine the frequency of uniparental disomy in Prader—Willi syndrome.